Spincaloritronics with superconductor-ferromagnet heterostructures

• Applicant: Professor Dr. Wolfgang Belzig
• Subject Area: Theoretical Condensed Matter Physics
• Term: from 2014 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 257730597

• Final Report Year: 2019

Final Report Abstract

We have predicted efficient cooling of spin-split superconducting devices using spinpolarized currents in multi-terminal geometries and in the non-linear regime. We have developed the theory of strongly spin-dependent boundary conditions for quasi-classical Greens functions to describe electric, thermal and spin transport far from equilibrium. We have predicted spin-polarized Shiba bands at interfaces between a strongly spinpolarized magnetic insulator and a superconductor, which can be used for long-range spin transport of heat and charge. Our results pave the way for the development of energy-efficient, superconductor-based low-temperature heat, spin- and charge transport circuits, which could be used for information processing. One of several articles was covered in the media via a press release of University of Konstanz and cited by several social media, e.g. linkedin.com, phys.org or eurekalert.

Publications

• General Boundary Conditions for Quasiclassical Theory of Superconductivity in the Diffusive Limit: Application to Strongly Spin-polarized Systems. New J. Phys. 17, 083037 (2015)
  Eschrig, M.; Cottet, A.; Belzig, W. & Linder, J.
  
• Nonlinear thermoelectric effects in high-field superconductor-ferromagnet tunnel junctions. Beilstein J. Nanotechnol. 7, 1579 (2016)
  Kolenda, Stefan; Machon, Peter; Beckmann, Detlef & Belzig, Wolfgang
  
• Creation of equal-spin triplet superconductivity at the Al/EuS interface. Nature Communications 9, 5248 (2018)
  Diesch, S.; Machon, P.; Wolz, M.; Sürgers, C.; Beckmann, D.; Belzig, W. & Scheer, E.
  
• Spin-splitting induced in a superconductor by an antiferromagnetic insulator. Phys. Rev. Lett. 121, 247702 (2018)
  Kamra, Akashdeep; Rezaei, Ali & Belzig, Wolfgang
  
• Spin-flip Enhanced Thermoelectricity in Superconductor-Ferromagnet Bilayers. New. J. Phys. 20, 073034 (2018)
  Rezaei, A.; Kamra, A.; Machon, P. & Belzig, W.
  
• Yu-Shiba-Rusinov bands in superconductors in contact with a magnetic insulator. J. Magn. Magn. Mater. 459, 276 (2018)
  Belzig, Wolfgang & Beckmann, Detlef